1. Technical Field of the Invention
The present invention relates to a stepping motor, a printer, a stepping motor control method and a stepping motor control program product.
2. Description of the Related Art
A usual stepping motor driving device ordinarily employs a method in which a table showing a relation between an angle of a rotor of a stepping motor and a phase of excitation is referred to supply an exciting current corresponding to the angle of the rotor and rotate the rotator to a desired angle (see JP-A-2002-281788 (Abstract, Claims).
In the usual driving device, when the relation between the angle of the rotor and the phase of excitation deviates, an accelerating operation becomes unstable at the start of rotation, so that the angle of the rotor deviates from the phase of excitation, what is called, a step-out may be undesirably caused.
Thus, in order to prevent the angle of the rotor from deviating the phase of excitation, a technique is proposed that when the stepping motor stops, a hold current is supplied. However, in such a method, a problem arises that the motor may generate heat by the hold current. Further, since the hold current needs to be constantly supplied, a consumed electric power is undesirably increased.